Spark Plug (97506) - BMW N20 / N55 / S55 / N63 / S63 | 12120039664-NGK

Spark plugs are an often overlooked maintenance item. If your BMW has developed a misfire, studders, or feels down on power it could be due to worn-out spark plugs.

Please note Tightening torque for this spark plug is 23 ± 3 Nm, the gap is preset for OE applications only, a special 14mm, 12 point spark plug socket is required for the removal and installation of this plug, please see p/n 83300495560 for the correct tool.

NGK and offers 2-step colder spark plugs for the BMW N55 engine. These colder spark plugs are recommended for N55's who are running higher than stock boost. The 1-step colder plugs will likely need to be changed every 15,000 miles, on heavily modified cars, or sooner if the engine is experiencing rough idling, longer starts, or misfiring.

The stock heat ranges on the N55 are one-step lower than the N54, therefore these plugs are one-step colder for the N55, and two steps colder for the N54.

Why Opt for 1-Step Colder Plugs?

It should be noted - running colder spark plugs will not necessarily increase power (although it may restore power if the current plugs are old). These spark plugs are not recommended for stock boost as the spark plug will not retain enough heat to burn carbon deposits, thereby significantly reducing the life and effectiveness of the plugs. If your BMW N55 is modified, tuned, FBO, etc., the 1-step colder spark plugs are the best option. These spark plugs are more efficient at transferring heat and reducing the likelihood of engine knocks or pre-detonation, which becomes a concern at higher boost and horsepower levels.

NOTE: These spark plugs need to be individually gapped to 0.020" (0.508mm) using a spark plug gapping tool. Additionally, these are the OEM plugs for the N20 and N26 turbocharged four-cylinder engines.

Specifications:
Center electrode core material: Copper
Center electrode tip material: Iridium
Electrical terminal type: Non-removable nut
Ground Configuration: Standard
Ground electrode core material: Copper
Ground electrode quantity: 1
Ground electrode tip design: SPE (Square platinum electrode)
Hex size: 14mm bi-hex (12 point) - see p/n 83300495560 for the correct socket
Thread size: 12x1.25mm
Torque spec: 23 ± 3 Nm (~17 ft-lb)
Insulator Height: 50mm
Manufacturer heat range: 8
Pre-gap size: .03" (.762mm) - Pregapped for OE applications 
Reach: 26.5mm
Resistance: 5000 ohms
Resistor Type: Yes
Seat Type: Flat